SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd40848ed7e67048c9f6ea55a27d456047330a310e7f7f2f041c253335ec2725b' 
  AND token = '2fgpJyzmTqaCvz56Bfz+nCwn4nyMsCdyUR4lOlBbOsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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