SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdb100cf6c20de0886b0bfaa32bb18cbea5f074d6c62f924d8cd008472d0eb71' 
  AND token = '7qpE25UfsBfiURf8AUwWbDYWaavixfi74pzdnBxmuLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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