SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edbf2bf8288599dd52863cd3e6167b66dd52921ec367337a761d9ecb0413747f' 
  AND token = 'MCS7OrzoaSfb2s6D3dQ7urFzgKckzph3meXDpAyjxoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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