SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e44ebc190e8fc52baa85292cff77218f0dc7b53420e187c37198e49f68b809d' 
  AND token = 'MMyMoVfAyitTOXtM4Ty8ZsOWiTdSBO3UHaznmxtWFFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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