SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55b6633f913bb3d980378c76c375377fbc5b647a7d8f53c8c774edfb67d939e2' 
  AND token = 'ABuZJvBMiSzxrPcJddCHABGHwU95Shi8+Mbk77bO8OY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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