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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3de9508ab75146a2f1ff5c39e030b0ae8b7bbf5aca7aa6c7dd1e1703d2514d60' 
  AND token = 'KgxLPe43u93nTs/6TWvQPTNTg5oFJJr+BZcZpdwBu38=' 
  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"
    }
  }
}