SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b143ed0f8359704121689ff19215234891b2e1ae5a8703066f8cb654186caba' 
  AND token = 'gwr05iihrR2Q7ouennSrz24grvOQRY8watY5o8QhDnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}