SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec6075dfb1555f8d7b2d276d3c15265a5b26d73ac2bb8cd9142a5958d056dded' 
  AND token = 'SOwPGVGqAow2iCSFPe3s/dBKabS1ZnfC9Mh8prdMzAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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