SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ec841258b7133d78f06036ac702d2b68c7876b6c692d9ec99f2ebe6b8cb67a3' 
  AND token = '5HM/mkVp2KJpqP3d3Vez6BBvfA+bCk2JMNnUj3+p0yM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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