SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06e6bcc02faf4ba4754967705d2130015314e4fd190b40b38c896b570031a19b' 
  AND token = 'kWrMnW//1UG/pwDNtON+JgwAReYMyiwdGvfKKcnFpFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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