SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b94978ac45ac166ea72ea45adf732bc0c2bc43ce97631b85438eca514f1db18' 
  AND token = '4TMe24/fjZtlCWnYPSPgLIaCUfeVV6kjZGiQvX1FlnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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