SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '290b437a63ce9fb3b10a3cff3df3c4ce694155fb650f7bf7a1d68bdacd6bc441' 
  AND token = 'OjkCiaJTrYrfhgDxvUOfxGDNb95fZzv8IOIrDB5YhEE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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