SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30640d89b1333c8b4db736eb99c51ad36f1fa125777e7adb66a2196330c6030b' 
  AND token = 'DVPXBxqr4lHedU/GeeL+7ZSPG08HZk0vqyK/acBwPP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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