SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8427804bcc784c7bb2862d966c0c383139bbe543ae7b4942d7dae53d1e9d5d6' 
  AND token = 'TvfvlQzfeUfstH/pm+Ds8x4lkvk+8/4PB9vIYuGvhoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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