SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30c3b2a9210c3357eda43792ffb2695ba362dac794ee9dd687e6e82f6dc9301e' 
  AND token = 'n5ERi8pGW52eUGZtv2QYW0J0tCgqnpUkiZWxdOGi5iA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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