SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8acbe151eeddfaaa380ceb4518b99cf7938639573f686d979e45df7b2b1a6ea7' 
  AND token = 'LuKBOXuGLRtrbsSdZ0ykioOR1af1dV5fMgq9etiFBDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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