SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f26f0d8d0de78589c23436dca51577a2f6533333619362139dd62f5091534df2' 
  AND token = '9OGG74zS/kZFQPg6EPzQWgK1f0AoAZGWb8NNWWjL5Mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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