SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78d7accbf38d215b17a262397df0012f25f64055600109d4555aec8038d66b9c' 
  AND token = 'mZzBq/+PA/ADhdLjnPkIAm36Xu6w3ovIYG/N+LF/A30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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