SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b0b0d579a941d6e14d33ece2a9f383bf12a75c7ece4b34adfefe50bcc9ce704' 
  AND token = 'YDKyjz0kt1H7wg3As7wViOdDT6L9WbomMDMBGbi0RWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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