SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4124f4bde35fd9a958443e268962a6b09cf768ea8db15b4ffb83dbbf1b8ef9e2' 
  AND token = 'lDNb5h5RxVb9ILXaqZJfHxjPiApVJLhSgvrz/mnRMjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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