SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '14e43fce464faf8023413435c9e966bd70a840590cb0b04de3cbb705d5878692' 
  AND token = '/OlytYzS7nyyQ8RQcaqD1JpCSh7hUOunmC3/eWh+vJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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