SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c77f4dcb159a8e9fc0ce2839462fdd70764761a89d604c8269503a3728d201' 
  AND token = 'jvkDC7UfAwdKruHXAqGs9DnGtHzvFGj1sdX1smzr++g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}