SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33a3604a13eaa5e0a1fd2d95af2a01821f9b3ba4780d6c8e3a9b4e72ac463ee1' 
  AND token = 'aIe6chlC28KdKl74zweWMKTijKwsZrnxNj3/xcL9m3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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