SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8abc4632315180037a1ec89efc71077916a4af1f8aae89b1c9a4cd6738a1c0bc' 
  AND token = 'H+MfTXgYz4fKRurTmRcOLjbTtze5Lm99qtim1cZ+XR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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