SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '141d21b0e8836b781d1a331d9c47cb28fce2577d36f49342cc2e950497c53995' 
  AND token = '2BHYQ376ZU074jxScKviyWjHH9AqRXCCFtElS0zVC8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}