SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '212d24cbbfbc353689fe2745ebd3bc693dba09bd731f5b66b72f5f0828671a46' 
  AND token = 'Yd9TsfS2s7uJ5K+EtPkfySNp2PfzJ8ja9U4l6L3dXeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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