SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9c26a7ff8ab6cda949d3cf13e4b4a97f264703f815a3b14a6a110aa93955e85' 
  AND token = 'E0M3gh1JgxwnKDQlGRhCxfTBvJIoXYD6wbM0nj/ylSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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