SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3581e76f56f7a8d08270f9d799bd65be01b6e9f58e4953ea800a2b47e1f635dc' 
  AND token = '5X+NUoDY8fTmOsg+agilItGUTWZVC343B/DzGsd2vGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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