SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bde74b27f3a88a2dac6d2507bb6c86e2ac7af71a5608b6f6be362aadcb9f4467' 
  AND token = 'N0iAS+oeN3hG097NaCS5LGMYfzIpxotem/0xMZmuE8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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