SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88eb5eaba9eb3260b59834fe29a99ae362d38c030c974dee46f41e023a2c5d52' 
  AND token = 'VfuDJeuAAYvanfQRwLhSRmBfuph8wvmWIpEdcHNGpxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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