SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1aa5f782fccb106a7eafcf12f465c16aeae2c777396a475857b1b7df2e0992e8' 
  AND token = '6BJZF9N7JnlHYCsx++A3YVOwBNpKCzPFOnbYNkvsoTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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