SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b73d8552811de54e6852453b2bbeaa67feaf106c737a23b8ecf04a4a955af8fe' 
  AND token = 'WYC7fnUaIfb8OdvxIMQAuLV+lxB5/kw/BMFb/HNgFng=' 
  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"
    }
  }
}