SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66a46ac1c80ebdfddfc5aae737be687eb96054ca0dc04b534931019e249a205a' 
  AND token = 'nQTcXBBabfOWKwBSUAWGzHe+/hDGdS765k0aVJP6IFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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