SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ac22885d0ddd90394747ba2550956004ee5acade003250d8d39b4b3be46a69d' 
  AND token = '6njRRvUO+Zqi7tOyLFGJfHSFtuhGs4ScpTobvLPApLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}