SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af30cfb83eacf92d3d7fb4eeda16f622c852923167cf487a3f0227de9fc7c63d' 
  AND token = '8mpZ+PWWJUKiXDex4PVb754gOvcZIExwfKa16luLY1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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