SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48488199fa36134bfe38da3138a82a3da3d9402dd2f811a6c2bc948ec907637c' 
  AND token = 'Px6hvY497qiJGlNuxRjYTdY2BSiHzo/ynAu89ZmWwyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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