SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd9f6d549d8f1cae682ea7efe63dee9384055956c428df23001d0c1cad88adcd' 
  AND token = 'OQHMCb6zA7FIZ2WPdEfiKsM7YLsaUKLY5NzAZY12HK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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