SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '193acff60dc2491a869005fe1ee3edfeda2c821b2dcbc9b98e39f69fd19a0ce7' 
  AND token = 'u28cBMEaPWAi9lNWpkWQHXEsAzNTsO952hMhAof9FhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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