SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '469c5e7ad18e3aa7594b4b02655b1518e3cc9dfb78c1e46ad0d3930cd7a0f41b' 
  AND token = 'HKQsbAxixhg1gM/6YsOPR8Mk/ODMKYIlE66vrp4XZNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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