SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e786988fad46d1c11252ce01d24f5b53e386e770dd4df200ac22648d42c7688' 
  AND token = 'oLuWIIsOdXJb9OnxmNyxst9KZem/gqV012ycawx7FeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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