Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2d4ee66d253e23f652f7434dba27b3fb78e1e96676f3e190f1dee88ddcf5a6d' 
  AND token = 'QE6gXxEvxfmw+AMsd9IwnDpFU9NI0Vt6Ka5jqqf3RxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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