SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49d1e41a610c097c86edea45a25946c517ef5fc7f419ca7cffce224be7306f99' 
  AND token = 'KU6Jd+Kj6M2Xg04VeqIG+vABa2VHsViO8dH88oxOsCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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