SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b3d0333262afc87df60dd430647f6239bb7c81694ff2a903013fdf5915da12b1' 
  AND token = 'fAzoV/MuolQPeyx9hUMLCRdsUB/S7wz5NVv89GiZj1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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