SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fce2e5e923bc02140e4cc87f53fb970067e6164646497c64de45835bc1311ec9' 
  AND token = 'xpCBmYoKi63CRwhmIJnQ3FUDK3gnGXfOxmdPpGBooXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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