SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3c8aca0fa2061aa7927fd2e59fda71f7ec15543fad6a9e62a3d30053c851aaa2' 
  AND token = 'Io3jml2ru6cnR17SZtQcCngtxTKQ4HRIWOj3Xb1p1RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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