SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '067e1897bd8f0c4716f78512b1670c347950d1ceb4db7f4a212a7e7f05d0cae9' 
  AND token = '+i8nA1ifgkTFSYuD8ZGI8btlrW5gqiUdW4NhYYHXYbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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