SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '384641ab6237f59a4e0eb02ac5ae41fc6c7ec7d6322246818b3ad8b526fd5459' 
  AND token = 'Y4zhG8wX/0YVoTlAzlRKFC3lnn5Im37aXzgOPhM6jPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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