SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4308251d7b75a2e2bd49a908e0b56b05fee6053625dd2598dceec325030c0d52' 
  AND token = 'S0GDagLxjFspEXAbGkWWNMLwUw61FeoBOceIOiZkYCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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