SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fa696694881a9ec8c67769ffbbdeb99daac69d79c19d4a44cceb76e16276fbd' 
  AND token = 'ToiRC5Kp8wljWrsFxSgNhM3M4TLGN3F7vFDaWO5+zxE=' 
  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"
    }
  }
}