SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '730c14bae9e1f39312f0ae119e37ec62e42eea10ba15655bc3807a4cf6a089fd' 
  AND token = 'gxQRfMPIbc5EZLZDSmUV2xCIUmju+6SyF32pBFtbZbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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