Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c617aecf69816aa8009e71e5d575abc42c0d1a24d2b07420ab91d506411f3f3c' 
  AND token = 'WCrENC5AcRdpkxhVz2NErvwIPp/1xz7UJP5guMFMuaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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