SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fc8cf35dde59f8c3a2671ba143e1559deca416fa8ecd99f91acf3e2a4d0c928' 
  AND token = '/5iszo98/DirjqqIVezurh3wHceYjCqpdpxQQfzdLLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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