SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf84a7e198479b3aaaed5b6b740c5e734497eb2f869fdb33b560ca858875f90d' 
  AND token = 'qRvjVHf+xhwy5F6QAX97LxBv1W7HU/yOfmcBV1J3dSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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