SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a34fbb38605cac674f50462e5ee2f6a68556a68f61c8d567269b5603e26a5085' 
  AND token = 'oTozFTKgIUznbsO4RYm66XWZlqYXgYrGJRLOaw4Syg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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