SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dacfb8b94f8400938c8a14fc83a9b9ebdc216e570da5385147d3236fddf14f09' 
  AND token = 'Pihi234XTN8etWbr8ss25dLzPBLPCtRArLNh9LhizDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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