SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36bafb56a27734f3a7a38317dc13a1ab6f4099ef3178a7a3641980f37f8cf495' 
  AND token = 'FEjvmn8FxG7wfVKdjxcG9Ib1CUpDYYF+nYlzo/j1WX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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