SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1df7bdd1244cf5f86caa770af199debe298371fd123406835f3d92ce125bcd3f' 
  AND token = 'xfvaYUkiSMzTBRWXjjKYgtUyvXB/THOmyXPlDNpWWc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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