SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9ea7d2241a7fad12743624703bf8f31d18b2b1082d88e2dcb8e90d213f8c87a' 
  AND token = 'dpR9ZMWECpu3nrRPYPAtfS7t28C8TONiEYDdqtz+USg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}