SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '183a3a2b0f1198896852a10203a13208debdbe18115e5a35f2fdbfff8b013fe0' 
  AND token = 'kHO7FYYyd0osoSpcVjuOjnWwljXR4n2odTY4DvpTwW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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