SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b238a4f17babe1f62241a1a3aefedbbe611fccdb66444a90df0ae1121b7de919' 
  AND token = 'Tf1viWTxu1s4WCogb8hNql1qtozGSqddY2776ump8Ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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