SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d41e057285a0c81db623455f9ca1b4366fc71d06fedde5e02f25ac5e214f9b1' 
  AND token = 'Jg2AB1F8qEZXugjPwoJNBhMi+BFIxxPVmGC1zvdN4+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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