SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b168e71b4eb47a094a8244ae4ef08f681287ef7293c5d4c914ccc546a657562' 
  AND token = 'ddeEx03OQaljdD1xxVwCFodzhvh9ryJZX+CPy7qLAgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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