SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c04d3bb826815df695af83b237f6013a2d7d7359bc88ba73fdfe64516e6e16b' 
  AND token = 'fezv73Oj9WS8lu9pxikxcLXCfGryAtrPUV9Ufpv0kIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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