SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7dff9cb0fc868567e37392491e0b581645b7f7f5059ad71dd22f2c37a56c0b3' 
  AND token = 'qptkzLiwI+JTAOF+9uHkhh9jqvi+sqWQW0N8G++i0YE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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