SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd55ae6eeb9038b744f8cc4a97275c284a24a44b528eecb51ef504149c018f3a' 
  AND token = 'OfLvMnAKizU2Unm0hFPlOjvaCci7KS5YSOf2gncIbjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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