SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7889dfabf10c6c9f02f94d852831d544f3bef6193b8303c7f9d8cd48dc9cba7d' 
  AND token = 'kdYzhnNzKVYSamWwdmoS9C2o5uFql+HI6W/Q3U6Mpwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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