SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ca27c033ec72b1a74e4c84d24fb93dbbdb62195df1e25ae04858e33ff68bf9b' 
  AND token = 'qorj3Xn/s1WGKVqUgM/HqHrkmb0iZDDF4SfzJXW6mX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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