SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '193ba6565e54d7b2ac61509d7257015fcff804a55b93b75acfbaae1b7d68b68d' 
  AND token = 'MViShGPYh/jvRbO4HNvkOp6tOR6I6h0HGdgPSo8O7dE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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