SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e482d77fe9c7a2b3e9449d3afb26c72812eb59febc35b073f128db2ef939b3c' 
  AND token = 'AUh0yOmtFC2XRh5RlbVTF86V90T5hGxlHNoE9RRUup8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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