SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41d68befd48a42529a4ac8a5fdf738c9797415500243e697cd7b3b4912a71538' 
  AND token = 'XiXxUsjBS42he50xSUDtCs9yuR8X6iE2ju6TGRqd3CE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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