SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '418837f5fc5bf6fc771e7d16d4c072d85237e7db218fdc95f78e55d53260f1a5' 
  AND token = '4PEpzkcYMfc3cYAhlDPRaAbubDHWtoKuPVvC/qHv7aM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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