SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4380afab02341e40047552e632a18aa3826c496da6b89f97ab7cd0893879a972' 
  AND token = 'dmHfy9MzVwJWXLVJVLhvtnwFKEghjJgVL64V9OBF1hU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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