SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba2a83c845ef996a9923426e56db48d81924b2eb0a53c0e834c7bade07ec5d19' 
  AND token = 'tkfUsLcGggRXz7KLSQX9NdfCAGRZN5pSyj7rHokBbDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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