SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1384b192c3c6979a1accc343500b6dc2ae0b5706d9af72212bf117133ab2cac6' 
  AND token = 'avrVkXAQ4DNrDkfQy8n4X7KBx3tDz1J4d9XtwpoRPFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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