SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e3d599ebc15a71307b3b65f88d1a69339f3142923ea09a3a26757feab9dc7ee' 
  AND token = 'hhqGKRt3P1djD/9Wy9M0M+DVV+jBlzDBxFo1ZwVitxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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