SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9192eec9a3d9540873681eb0d7a105cc0eccf7e7ca2d540efe196a73389a1a98' 
  AND token = 'WpLmyxHhmQQA6c1clzUwSgTvS1Gik2bbTSj5WVkVnRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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