SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '598ac2dd6e51875149d5a8c69adeb615a5f33a483de209584f5211d7c51b250a' 
  AND token = 'rOAW2masd9rLQeVhWG7tf8jPCkWLhJvB1CDLx/cEkVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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