SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acf7972edcb4430b42c8a081932f6daf91488a1764bebcdc1f55f03fadc7ff64' 
  AND token = 'CvSW0V90TQpV2mFZQaBHMkU5qFPo8jvITSf4dy0l9VQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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