SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a35b089bf64dce2e5bd52472eafcca18dc4a80688266bd7f20f4bee75128772' 
  AND token = 'Gx9Jz7x2WRV/nIrWIkhBxHFZOW/MX5TCThLuwc2qPx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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