SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7149e071f00c992efebd3ca9904f9931470f18e15dff2e6ce1ed105b58a4b12e' 
  AND token = 'zPWbZmPCeh5dcK3BSdXZRMXYpZCzyQM3jKhbsweud4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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