SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9af1e99d4f318f49150ae08ffdb7e98930cb6b5e82f7f0c388fe13808cc85c0c' 
  AND token = 'BRkh8MtEZsGAF2qOnqoJZ57NuHy5b+XkJBMY2Z+bqps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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