SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6803164b1ea8b543818ad9a9fd68cfaa237f0ec723575a1aff22348189206452' 
  AND token = 'RyATsuAlkOtZLLq5GqaE/xBb4JKPygghALtLLhAx2Tg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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