SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c57b59c4185ea8537f24c1c336f97bf0423928998b2834b25924495ab2eb5a10' 
  AND token = 'FJvWbsz5/mejBKj4chBpCCjLnoZIVCiSUdctXD/LF0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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