SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecdefdf375b2114083569104d7cea1c3fe1dec5759749c4e3fb12f88697da68f' 
  AND token = '3yh6v9IfduNslxz8twSrbaKcx5/DsaSH0GbuUo66E9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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