SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98442db95d6e9de182522c5453ba142315bff6abc1cac43e74303dfed526e392' 
  AND token = 'yzF6TNM4DhYxk98QvmIKbFrOi7TITPvyINXzR8iKv6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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