SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea170d23809ef4b610eb85e20a96b9b1519d13e8bccc4ee21937954e87e77040' 
  AND token = 'pbV+HAi+9C2PnbZLUa8vggMCfAE9xpVpvdX3shhG55Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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