SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cb18fa8bcc352b514f3c44cabce9feb96da6e7286db19ac59bf27cbccd42cdd' 
  AND token = 'bFYrgTs/+d6jmyuLVYXrhFOHwPolIcrX6lTF/0AVS9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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