SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '274828a674237fa3750ab5a8fe1f3a26859a680ba659cae4cf76167ddfd84592' 
  AND token = 'aDAIGlGaFwRj7t2tsmx4Hjq7aEpCLvs335eGeK7XUrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}