SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10486301665ffafebf708145cc3d89dbadd919cc48861f3a5e0f5ab1f4923943' 
  AND token = '0o3PKqhNg+Uxbi2EpocO/c5uB2/0eHUpi50uno+Uu80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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