SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be30c16db21862a18535841091709fa8e287445d303d588394f5e93de673ccf0' 
  AND token = 'zPP0GbWIsFgXz/tNy6GZoZWIODK1vT9gHZlMbfgVxGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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