SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72891b9cdd42aae2d4442a80bf2d82bbbecefaa874d711d6877a3e98c099672e' 
  AND token = 'TcNsx4I+rKHnbX1PCN3sGrEVwHRMRXM+B1RQyMzGgCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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