SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd67fe3817abcc336ab04a5cb74fc5821b7a6f25997c31d7f298248f6e8951ede' 
  AND token = 'SycKz/iRUgnF/ZFzHTYRgal5z08rzlUN1Kt9JM6PyqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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