SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43f221d54c5f93e80a9088ad47da88bb6ef7a6a4bd871085ebd963eb643d6378' 
  AND token = '57+QvEfqu+kGqGLXhK+9RYUnD5gFUpJoWRr5q7conbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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