SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1831c90728f2d6e82e19250d207a6ead4b69a00b44a39b8e0ab7d9d1b70eeb07' 
  AND token = 'qY/TJAwULOpYugASdj+DhgQ4wqVNGKipYK0uoGh9fGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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