SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bda6da044ba10dca9cd801f984b07dd228ffb8896f50d332fbb6a0b8f628b5b2' 
  AND token = 'YRjH4pNIQXqBO2xVDqW6qhwAbMRxSFumhJ+TEO/CTrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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