SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ac0ddb0a9ce644164774eead65f6f81fa26e8167da6367372413c27dddb1df8e' 
  AND token = 'N1eUTEyKz5Df2r4LywZYM8QZMVjD0ysTY/FvAu8iPcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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