SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de4abca4837df9e95d1df7dac0aca82ee5364271666689a0c7ecb5cd4b259340' 
  AND token = 'osgVyzXYsRNasOcxzRh3MInotyzMNIcX70KvGYP9s0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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