SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82cb51d1da9a559061b355566395b78bb931d0a792ec73bd4d65bc14130e3ffe' 
  AND token = 'DGuekUnZyBl4kPjoK9fDqN1+DHS8/3FmGxi80rAetng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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