SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae352b6c3319378948a00c6e6cec162d2829e6ac1391efbaf9ceabaf28b9f72c' 
  AND token = 'R8jcn+OYg4Fn0fmVIYbN7E1Q1kHo0ikT+dSv/3wmiSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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