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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbca62047f829c7ecb2bc0f7bdda5d2479fe08f88e776e0edc4f9be5dcbf4b40' 
  AND token = 'f7VwLVb8GjLBZCcL2oPxx0sow2Vz0ApHNjhBFyGT4tI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}