SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecd3978ce4d78957fb2e18669c54ab16bba0b82626fa25fb4c9ce4e5ea03b366' 
  AND token = 'vWSkYY/Ht7exbR50aem5HJnFpCDub0jrCaEdYHGTp0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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