SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36df33c8e506673a0dd650837c7ab61b5f5a56ec64946ace6fda5731a6cf9ffa' 
  AND token = 'WGYPW8YA8pgvV5IPJfnnjmzZK/1NiqUuEuMS+0Rs5ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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