SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '155181e0cf84c5a5644cdd024cd090c655b81bd3f77c0bbaf1b06e59838bfaa7' 
  AND token = 'yxVE6WOpt6QGrQz92ZGA9A67R/CUebrBntxotjoQLyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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