SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9da7d81eeda45d5e7af40e7e28333036f6fa9880aa81659ff092ac04576dc1e2' 
  AND token = 'QYozg3b9DMCJJ/E2ZKGvisGQPtmjBBlRacQDnp/Ui6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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