SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddd37706caa3d0ce1847ceee3688f00c6cf6265b21a9f982f7f224d44368fa11' 
  AND token = 'Q2tuEXhp018Zvx4AQYGJkWAYN7B+m9uENMYzM/GkbeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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