SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c948b7ec09e04b72ea61c49acc97848eaed7830bf5527050b71589765d1c291' 
  AND token = '4YtGiPc7OfmS2edjBhFKTj8mdULFc7BiZll4+Ku87I8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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