SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '013ebf6689e388c2ef1ed2e2cb727f03d38c1d1d2f9981d9dfde4b41d948c5e2' 
  AND token = '7P4o/XUK7zj9EWnNIywQJtQs6xYmZ6nFtVR2bBYr+4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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