SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c90000c93f113f5d65a900dc01245a5ed83ac749526dad69668db0356f81203b' 
  AND token = 'KlGgFr3ddlm1Ny3a7Wk35AODRsc34Ilannq6hoMCh2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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