SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33acb5449f5bb1fb43b57bb55bbe551f5d42c29ed1f9692335227576dba77084' 
  AND token = '3oX00xSkA7auzMvO4zcamEAe8TbGXrtGPqR3JC+rf8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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