SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '38b0ecfb1379f31bd2740f438edcaefa80a57353c485cbedfbe6e815944591c4' 
  AND token = '7lto/GjCoJuJFSvGTj486OyX9QeK5JuJ9xi1JQU84Eo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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