SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d0a2d6b5465bbf537323f44edd0f738e2a5932cbc8a566e8a481caa4910f6d3' 
  AND token = 'h96BT2Z25XJpzS4S4bjnomrWSOzyKLxWzvqmDGvFmpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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