SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d751772b42168ff7e780ecd08bb448bddca380a263059d88560104097965a6a' 
  AND token = '/qOSozL76ZspoFJu6+jpdsGytPbKGhFdqkphnsOtwk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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