SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f3fac1a576afb47c7c35ddabaab84373d268f14542c769e11d10dfb2db40fe0' 
  AND token = 'xUGVj7yzCqwMV448cDsmOLL5qWCjzvIuYLpXD7qShrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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